Optical reflector structures, e.g., mirrors, gratings, and layered structures are of obvious importance in the field of optics in general, and such structures are being developed further for optical communications and information processing applications. In particular, for example, reflector structures are used in lasers, e.g., fiber-optics and integrated-optics communications lasers. Preferably, such lasers are designed for maximized stimulated emission and minimized spontaneous emission, and reflector structures are sought which contribute to these goals.
It has been recognized that spontaneous emission is diminished in omnidirectional reflector structures which form a three-dimensionally periodic, face-centered cubic lattice. As disclosed by E. Yablonovitch, "Inhibited Spontaneous Emission in Solid-State Physics and Electronics", Physical Review Letters 58 (1987), pp. 2059-2062, such a structure can be made by successive layer deposition on a corrugated surface having a checkerboard pattern, the resulting structure being composed of cube-shaped elements or "atoms". Alternatively, as disclosed by E. Yablonovitch et al., "Photonic Band Structure: The Face-Centered-Cubic Case", Physical Review Letters 63 (1989), pp. 1950-1953, such a structure may be composed of a face-centered-cubic lattice of spheres.
While, conceptually, face-centered cubic lattices of cubes or spheres may appear as the simplest, they have been found difficult to implement, and their performance has not met expectations. The invention described below is motivated by the desire for a face-centered-cubic structure which is more readily manufacturable and which is highly effective as an omnidirectional reflector.